Multiple cross-site request forgery (CSRF) vulnerabilities in the XML-RPC API in the Desktop Client in OpenVPN Access Server 1.5.6 and earlier allow remote attackers to hijack the authentication of administrators for requests that (1) disconnecting established VPN sessions, (2) connect to arbitrary VPN servers, or (3) create VPN profiles and execute arbitrary commands via crafted API requests.

Unquoted Windows search path vulnerability in the ptservice service prior to PrivateTunnel version 3.0 (Windows) and OpenVPN Connect version 3.1 (Windows) allows local users to gain privileges via a crafted program.exe file in the %SYSTEMDRIVE% folder.

Cross-site request forgery (CSRF) vulnerability in the Admin web interface in OpenVPN Access Server before 1.8.5 allows remote attackers to hijack the authentication of administrators for requests that create administrative users.

The openvpn_decrypt function in crypto.c in OpenVPN 2.3.0 and earlier, when running in UDP mode, allows remote attackers to obtain sensitive information via a timing attack involving an HMAC comparison function that does not run in constant time and a padding oracle attack on the CBC mode cipher.

Unspecified vulnerability in OpenVPN 2.1-beta14 through 2.1-rc8, when running on non-Windows systems, allows remote servers to execute arbitrary commands via crafted (1) lladdr and (2) iproute configuration directives, probably related to shell metacharacters.

OpenVPN 2.0.7 and earlier, when configured to use the --management option with an IP that is not 127.0.0.1, uses a cleartext password for TCP sessions to the management interface, which might allow remote attackers to view sensitive information or cause a denial of service.

OpenVPN 2.0 through 2.0.5 allows remote malicious servers to execute arbitrary code on the client by using setenv with the LD_PRELOAD environment variable.

OpenVPN 2.x before 2.0.4, when running in TCP mode, allows remote attackers to cause a denial of service (segmentation fault) by forcing the accept function call to return an error status, which leads to a null dereference in an exception handler.

Format string vulnerability in the foreign_option function in options.c for OpenVPN 2.0.x allows remote clients to execute arbitrary code via format string specifiers in a push of the dhcp-option command option.

OpenVPN before 2.0.1, when running in "dev tap" Ethernet bridging mode, allows remote authenticated clients to cause a denial of service (memory exhaustion) via a flood of packets with a large number of spoofed MAC addresses.